The present invention generally relates to an electrical connector for transmitting high speed electrical signals in differential pair applications.
Many board-to-board connector systems have been proposed for interconnecting circuit boards that include traces arranged to convey differential pairs of signals. The differential pairs include complimentary signals such that if one signal in a differential pair switches from 0 V to 1 V, the other signal in the differential pair switches from 1 V to 0 V. Each connector exhibits a characteristic impedance.
In that past, fluctuations in impedance exhibited by a connector did not degrade signal performance by an appreciable amount when signal/data transmission rates were relatively low (e.g., less than 1 GHz). However, newer systems have been proposed to transmit data signals at speeds approaching and exceeding 2 GHz. In these high speed data transmission systems, even small impedance fluctuations may pose significant problems, such as signal loss, interference, noise, jitter and the like within each connector.
Further, each trace of the circuit board is attached to a unique signal pin of the connector. Within the connector, signal pins of separate different differential pairs may become electromagnetically coupled to one another. When signal pins of different differential pairs become coupled with one another, the signal pins exhibit cross talk. Cross talk increases the interference, noise, and jitter within the circuit board, connector and system. Increasing the distance between signal pins of separate differential pairs typically decreases the effects of interference, noise and jitter. Increasing the distance between differential pairs typically requires a larger connector. However, electrical and electronic applications today require a large number of differential pairs to be packaged in a small space. Many systems require as small a connector as possible to make efficient use of internal space.
Thus, a need remains for an electrical connector that exhibits improved signal characteristics in terms of impedance, interference, noise and jitter. Further, a need exists for an electrical connector that may accommodate a high number of signal contacts, while reducing interference, noise and jitter among the signal contacts.